Incandescent electric lamp



April 9, 1930. w. 1.. CUMMINGS INUANDESCENT ELECTRIC LAMP Filed Dec. 20, 1923 INVEN TOR.

' WZL QWLL 6&77Z77Z ATTORNEY Patented A r. 29,1930

UNITED STATES PATENT OFFICE WILLIAM L. CUMMINGS, OF BERWYN,

CORPORATION OF ILLINOIS INCANDI ESCENT ELECTRIC LAMP Application filed December 20, 1928. Serial No. 827,325.

- This invention relates to incandescent electric lamps and relates particularly to a type of such lamps known as white lights designed and adapted for use in television, pho- 5 tography and related fields.

Objects of the invention are to provide a lamp of the type specified which will develop-or produce an intense or brilliant light, which has capacity for rapid changes in light intensities and will retain its characteristic light qualities through a wide range of intensity variations, and which is rich in actinic r ys.

To effect the objects of the invention, a lamp embodying vmy invention and improvements comprises the various features, combinations of features and details of construction hereinafter described and claimed In the accompanying drawings. in which my invention is fully illustrated Figures 1 and 2 are, respectively, central sectional views of what I now consider to be a preferred form of lamp embodying my invention and improvements, taken at angles of 90 degrees to each other, Fig. 2 being on the line 2 2 of Fig. 1,

Figure 3 is a fragmentary sectional view, substantially on the line 3-3 of Fig. 1;

Figure 4 is a detached detail view; and

Figure 5 is a. side view, partly in section, of a lamp embodying my invention in modified form, certain features thereof being indicated diagrammatically.

Describing the invention yvith particular 35 reference to the drawings and referring, in the first instance, to Figs. 1 to 4, in which I have shown what I now consider to be the preferable form of lamp embodying my invention, my improved lamp, designated as a whole A, is a form of incandescent lamp, comprising a hollow glass bulb a, which, as shown is substantially spherical and comprises a neck portion a,providing means for securing a base of usual form, not shown, thereto, for supporting said bulb and for making electrical connections thereto. As regards its usual features and except as hereinafter may be particularly described and pointed out, the bulb w-including said basemay be of any usualor approved construction and can readily be understood and sup- ILLINOIS, ASSIGNOR TO THE ELECTRON RELAY CORPORATION, OF CHICAGO, ILLINOIS, A

plied by artisans skilled in the art, from an examination of the drawings, without a description thereof in detail.

The lighting element of the lamp comprises a filament or filaments 1 and an equal num ber of field coils 2 electrically connected in series and mounted in such relative positions that a filament and a field coil will always extend substantially parallel with-each other, with the filament in the magnetic field which surrounds the field coil directly associatedv therewith. In practice, I prefer to use a plurality' of filaments and field coils, and the lamp shown in Figs. 1 to 4 is of this character. 3

The filaments 1 will preferably be made of tungsten or platinum wire or other suitable metal or substance, which will be coated with an oxide ofcerium or neodymium or other suitable rare earth having the quality of producing white light when heated to incandescence.

The field coils 2 are made of wire-preferably silver-or copper wire-which has low resistance to the passage of electric currents.

Within the scope and contemplation of\my invention, the filaments 1 and field coils 2 are connected to one another to form an alternate series, in any usual or desired manner, preferably by spot-welding.

As shown, there are four filaments 1 and four fields coils 2, but my invention contemplates varying the number of filaments and field coils to meet any desired requirements.

As shown, the filaments 1 and field coils 2, connected in the manner described, are supported in operative relation by means as follows: Embedded in a solid enlargement 3, formed at the inner end of a tubular into the looped are conductorwires 8 and 9, the ends of which project into the hollow interior of the bulb a. As shown, a field coil 2 is connected to the projecting inner end of the conductor 18 and the filament 1 associated therewith, to the'proximate end 7 of the conductor 5, a filament 1 and associated field coil 2 being connected, respectively, to the other end 7 of the conductor 5 and to the projecting inner end of the conductor 9.

As indicated diagrammatically in the draw ings, the conductors 8 and 9 are adapted to be connected electrically with an outside source of electrical energy, as the power tube of the amplifier of a radio receiving set, by outside conductor wires 8' and 9. In practice, such electrical connections may conveniently be made by means of a usual base, not shown, forming part of the lamp A, in a usual manner. I

As shown, also, the ends of the filaments 1 and field coils 2 other than those connected conductor 5 and the conductors 8 and 9, are connected by short conductors 10 and 11,, which formed onseparate wire arms 14 and 15cmbedded in a head 16 formed on the upper end of a post or standard 17 on the enlargement bulb a will be degasified to 3, the relation being such that said filaments 1 and field coils 2 wilhform a plurality of substantially symmetrical parts or sections as shown two-each consisting of what may be designated two strands, the strands of each part or section extending substantially parallel with each other and each comprising the same number of filaments and field coils, the filaments of each strand being positioned in the magnetic field surrounding a field coil in the other strand of said part or section.

I prefer, in accordance with common practice, that the bulb a will be exhausted to a 1g vacuum.

In accordance with known practice and methods, the metallic parts enclosed in the prevent the generation of gases in said bulb under heat or electrolytic action, which might impair or adversely affect or modify the designedopcration of the lamp.

As a modification of my improved lamp, I contemplate the use of additional field coils, preferably mounted exteriorly to the container for the filament or filaments and the field coil or coils directly associated therewith, said additional field coils being connected in electrical series with said filament or filaments and directly associated field coil or coils, and coupled to produce desired inductive effects between said filament or filaments and directly associated coil or coils and said additional coils, whereby,'upon the passage of electric current through said field coils, stresses will be imposed upon the filament or laments and directly associated coil or coils, which will produce variations in amplitudes the drawing, in

pass around lugs12 and 13 mounting said filament and ment consisting of or wave forms,

thus causing variations in changes or variations in input signals or impulses.

This modification is shown in Fig. 5 of which A" designates the lamp as a whole, a the glass container-shown as forming a tube of substantially uniform diameter, a the neck of the container providing means for securing thereto a base, not shown, 1 and 2 the filamentsand field coils, respectively, which form the lighting element, and which are electrically connected in series and are mounted within the container a in substantially parallel relation and substantially co-extensive with each other.

Except as regards structural details, the foregoing and other features of the lamp A corresponding to features of the lamp A, shown in Figs. 1 to 4 and heretofore described, will be readily understood by persons skilled in the art from an examination of said Fig. 5 without a further description thereof in detail.

As heretofore generally described, also, the

lamp A comprises additional field coils indicated diagrammatically at 18 and 19, which are connected in serieswith each other and also with the filament 1 and field coils 2 directly associated therewith, by the conductor wires 8 9'-, and which are mounted outside thereof and preferably outside of the container a and are coupled to produce desiredinductive effects between the same in the manner and for the purpose specified. I claim:

1. An incandescent electric lamp for the purpose specified, comprising'a lightingelement consisting of a filament and a field coil electrically connected in series, means for field coil in substantially parallel relation with the filament in the magnetic field surrounding said field coil, said filament and field coil having high and lo resistances to electric currents, re-

spective y, and a coating applied to said fila-- ment having the property that it will emit white light of high actimc value when heated" to incandescence.

2. An incandescent electric lamp as specified in claim 1, in which the filament and field extensive.

3. An incandescent electric lamp as specified in claim 1, which comprises a plurality of filaments and field coils connected electrically in alternate series.

n incandescent electric lamp as specified in claim 1, in which the filament is coated with an oxide of a rare earth having the quality of producing White light of high actinic value, when heated to incandescence.

' An incandescent electric lamp for the purpose specified, comprising a lighting elea filament and a field coil coil are of substantially equal length and coelectrically connected in series, means for mounting said filament and field coil in substantially parallel relation with the filament in the ma 'netic field surrounding said field coil, said filament and field coil having high and low resistances to electric currents, rev spectivel a coating a plied to said filament having t e property t at it will emit white light when heated to incandescence, and addi o tional field coils which surround the filament and field coil directly associated therewith and connected in electrical series therewith and also with each other, and are coupled to produce inductive effects between the same upon the passa e of electric currents.

6. An incan escent electric lamp as specified in claim 5, in whichthe additional field coils are mounted exteriorl to the-container for the filament and direct y associated field 'coils. I In witness that I claim the foregoing as my invention, I aflix my signaturethis- 17th day of December, 1928. l V

I WILLIAM L; CUMMINGS. 

